Global Positioning System (“GPS”) receivers employ a plurality of GPS carrier signals to estimate a location and velocity of the receiver. The receivers process the GPS carrier signal, correlate the GPS carrier signal against an emulated carrier and code at base-band, close tracking loops, and output a final measurement for range and range rate. The processing of base-band data is not optimal. Non-linear effects, for example, large phase error, large amplitude uncertainty, and 50 Hz data bit contamination (data stripping is not assumed), must be accounted for to accurately estimate the location and velocity of the GPS receiver. In conditions of high jamming to signal ratios, determination of non-linear effects becomes difficult, which reduces accuracy of the estimated location and velocity of the receiver.
Thus, a need exists for an increase in accuracy of estimation of non-linear effects of global positioning system carrier signals.